Finding the Fourth Proportional to 7,372.56, 10,172.34 and 5,139.12

Step by Step Solution

1. Step 1: Write the proportion equation
   7,372.56 : 10,172.34 = 5,139.12 : x
2. Step 2: Convert to fraction form
   7,372.56/10,172.34 = 5,139.12/x
3. Step 3: Cross multiply
   7,372.56x = 10,172.34 × 5,139.12
4. Step 4: Simplify right side
   7,372.56x = 52,276,875.94
5. Step 5: Solve for x
   x = 52,276,875.94/7,372.56
6. Step 6: Final answer
   x = 7,090.74